<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        // 复杂数据类型会引用问题 ；
        var arr = ["张三","李四","王五"];
        // arr.forEach(item=>{
        //     item = "hello";
        // })
        // console.log(arr);

        var arr2 = arr;
        arr2[2] = "hello";
        console.log(arr);



    </script>
</body>
</html>